1. Field of the Invention
The present invention relates to a solid-state imaging device, a method for driving the solid-state imaging device, and an electronic apparatus. The present invention particularly relates to an X-Y address type solid-state imaging device having a global shutter function, a method for driving the solid-state imaging device, and an electronic apparatus including the solid-state imaging device.
2. Description of the Related Art
There are two main types of solid-state imaging devices: an X-Y address type solid-state imaging device such as a CMOS (complementary metal oxide semiconductor) image sensor; and a charge transfer type solid-state imaging device such as a CCD (charge coupled device) image sensor. The CMOS image sensor is capable of random access to pixel signals, and also has advantages of fast pixel signal reading and low power consumption as compared with the CCD image sensor.
Most CMOS image sensors transfer a signal charge stored in a photoelectric conversion part to a charge-to-voltage conversion part, and output a voltage obtained in the charge-to-voltage conversion part. An electronic shutter function can be achieved by periodically resetting the charge-to-voltage conversion part. A shutter method of the electronic shutter function in such CMOS image sensors is a method in which a so-called rolling shutter (also referred to as a focal plane shutter) is used, which sets the start and end of exposure for each pixel row of a large number of pixels in a two-dimensional array.
A rolling-shutter-based CMOS image sensor has an exposure time shifted (different) for each pixel row, unlike a global-shutter-based CCD image sensor that performs exposure for all pixels at the same timing. When the exposure time is shifted for each pixel row, in the case of capturing an image of a moving object, the captured image is distorted.
To achieve the global shutter function, in the related art, a charge storage capacitor is connected in parallel with a floating diffusion part that converts a charge to a signal voltage in a pixel, and the charge is stored in the capacitor (for example, see Japanese Unexamined Patent Application Publication No. 11-177076).
Moreover, to achieve the global shutter function and also enable the signal voltage to be amplified in the pixel, two charge storage capacitors are provided per pixel, and an amplification function is realized using a capacitance ratio between the two capacitors (for example, see Japanese Unexamined Patent Application Publication No. 2005-65074).